1. Field of the Invention
The present invention relates to a shutter for opening and closing an aperture or an entrance of a housing. More particularly, it relates to guide rails for holding both end portions of a shutter panel slidably.
2. Disclosure of the Prior Art
A shutter of this kind is generally comprised of a shutter panel in which a plurality of slats is aligned in a mutually bendable manner and guide rails for holding both end portions thereof in a freely sliding manner.
The guide rails are usually U-shaped members having a U-shaped groove for accommodating the both end portions of the shutter panel therein, and in case an aperture formed at a front surface and an upper surface of the housing successively is to be closed by the shutter panel, the linear U-shaped members are partially bent in order to form guide rails that are curved in extending from the front surface to the upper surface of the aperture and are fixed to a fixing portions of the aperture by screwing.
In this prior art, since fixing of the guide rails to the fixing portions is achieved by screwing from inner sides of the groove of the U-shaped members, head portions of mounting screws may be exposed to the inner sides of the groove and is apt to be a hindrance in performing smooth sliding of both end portions of the shutter panel.
At a curved portion that is formed by bending the members, intervals of the U-shaped sections, that is, widths of groove for holding both end portions of the shutter panel, will become narrow and result in a larger resistance at the time of sliding, and it will accordingly be necessary to preliminarily set the widths of the groove to be large in view of portions that become narrow through bending.
It is an object of the present invention to enable smooth sliding of both end portions of a shutter panel within guide rails of a shutter in which the shutter panel is composed of plural slats connected mutually in a freely bending condition and a pair of guide rails including curved portions hold the both end portions of the shutter panel slidably.
The shutter according to the present invention, which has been made for achieving the above objects, is characterized in that each of the guide rails includes straight members comprised of parallel tie plates and interval plate for connecting central portions of the tie plates mutually for having a H-shaped section, and corner members comprising curved plates respectively succeeding to the tie plates of the straight members, and the both end portions of the shutter panel are inserted between inner half portions of the tie plates partitioned by the interval plate slidably, and outer half portions of the tie plates are mounted to a fixing portions.
Each of the tie plates is partitioned into an inner half portion and an outer half portion by the interval plate.
Since the guide rails are fixed to the fixing portions via the outer half portions of the tie plates, no fixing members such as mounting screws will be exposed to the inner half portions for holding both end potions of the shutter panel in a freely sliding manner. Moreover, since curved portions of the guide rails are comprised of corner members that have been preliminarily shaped into curved conditions, intervals between respective curved plates will not be deformed as it is the case with an arrangement in which straight members are bent to form the curved portions. So the intervals may be set to appropriate values. Thus, the intervals between the tie plates in the inner half portions receiving the both end portions of the shutter panel slidably may be made uniform all over the guide rails.
The corner members may be shaped to be of H-shaped sections similar to the straight members or may alternatively be comprised of a pair of curved plates only.
Because of the above arrangement, the present invention exhibits the following unique effects.
The intervals of the inner half portions of the guide rails for holding both end portions of the shutter panel in a freely sliding manner may be made uniform all over the guide rails, and fixing members such as heads of mounting screws can be prevented from being exposed to inside of the inner half portions, whereby the shutter panel may slide smoothly.
Other objects, features, aspects and advantages of the invention will become more apparent from the following detailed description of embodiments with reference to the accompanying drawings and appended claims.